Lake Zoar Authority | Water Quality Monitoring
The Lake Zoar Authority is a multi-town organization consisting of representatives from the four towns that border the lake - Monroe, Newtown, Oxford, and Southbury. The Lake Zoar Authority is tasked with the goals of improving water quality and promoting safe boating on the lake.
Lake Zoar Authority, Lake Zoar, CT, Connecticut, Newtown, Southbury, Oxford, Monroe
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Water Quality Monitoring

Water quality is a primary area of focus for the Lake Zoar Authority. Beginning in 2020, Western Connecticut State University’s Cyanobacteria Monitoring Program includes Lake Zoar in a weekly water testing program. The annual program monitors Cyanobacteria in regional lakes during the summer months when blooms are most likely. When Microcystin toxin levels exceeded federal and state limits, public beaches are closed. The towns and DEEP also test water at public beaches.


The LZA’s role is information gathering. The LZA also participates in water studies to learn more about the changing conditions of the water. In addition to quality, the LZA has an extensive program to control the growth of invasive weeds and as funds allow the most infested areas are treated with an herbicide that is used in over 150 lakes in CT each year.


Submitted herein are test results and survey reports for public interest.


For additional information, please visit:

CT DEEP Lake and Pond Water Quality Monitoring Program

CT DEEP Lake Water Quality Management

WCSU Environmental Research Project

SOLitude Lake Management

FirstLight Power


Local Health Departments:



Oxford & Southbury


  • Lake Zoar Treatment Notice

    NOTIFICATION OF AQUATIC TREATMENT SCHEDULING LAKE ZOAR   MONROE, NEWTOWN, OXFORD, SOUTHBURY In accordance with CT DEEP, Pesticide Division notification requirements, selected areas of Lake Zoar will be chemically treated with Reward (Diquat) herbicide, targeting control the aquatic nuisance plants Eurasian watermilfoil and curlyleaf pondweed.......

  • WCSU professor receives grant for bacterial research

    May 11, 2020  ♦  by WCSU News “DANBURY, CONN. — Western Connecticut State University Associate Professor of Biological and Environmental Sciences Dr. Edwin M. Wong has received a $20,000 grant from Praxair/Linde to fund his continuing environmental research. Wong currently is researching and investigating toxic......

  • 2020 Herbicide Treatment Rescheduled

    UPDATE: The 2020 herbicide treatment plan has been tentatively rescheduled for June 23, weather permitting. The lake will be chemically treated with Reward (Diquat) herbicide to control the aquatic nuisance plants Eurasian watermilfoil and curlyleaf pondweed, applied by SOLitude Lake Management.   The exact treatment date......

  • 2020 Herbicide Treatment Planned for June

    Lake Zoar is scheduled for herbicide treatment during the third week of June, between June 15 and 19, 2020, to be applied by SOLitude Lake Management. The lake will be chemically treated with Reward (Diquat) herbicide to control the aquatic nuisance plants Eurasian watermilfoil and curlyleaf......

  • 2019 Post-Herbicide Treatment Aquatic Plant Survey Results

    Report Comments: “Comparison of the pre-treatment and post-treatment survey data suggests that the treatment reduced, but did not eliminate, milfoil in nearly all treatment areas. Milfoil frequency in the treatment areas reduced by 15% to 57%. Treatment Area 3 is the only area in which milfoil......